The Relationship of Somatosensory Perception and Fine-Force Control in the Adult Human Orofacial System

The orofacial area stands apart from other body systems in that it possesses a unique performance anatomy whereby oral musculature inserts directly into the underlying cutaneous skin, allowing for the generation of complex three-dimensional deformations of the orofacial system. This anatomical substrate provides for the tight temporal synchrony between self-generated cutaneous somatosensation and oromotor control during functional behaviors in this region and provides the necessary feedback needed to learn and maintain skilled orofacial behaviors. The Directions into Velocity of Articulators (DIVA) model highlights the importance of the bidirectional relationship between sensation and production in the orofacial region in children learning speech. This relationship has not been as well-established in the adult orofacial system. The purpose of this observational study was to begin assessing the perception-action relationship in healthy adults and to describe how this relationship may be altered as a function of healthy aging. This study was designed to determine the correspondence between orofacial cutaneous perception using vibrotactile detection thresholds (VDT) and low-level static and dynamic force control tasks in three representative age cohorts. Correlational relationships among measures of somatosensory capacity and low-level skilled orofacial force control were determined for 60 adults (19-84 years). Significant correlational relationships were identified using non-parametric Spearman’s correlations with an alpha at 0.1 between the 5 Hz test probe and several 0.5 N low-level force control assessments in the static and slow ramp-and-hold condition. These findings indicate that as vibrotactile detection thresholds increase (labial sensation decreases), ability to maintain a low-level force endpoint decreases. Group data was analyzed using non-parametric Kruskal-Wallis tests and identified significant differences between the 5 Hz test frequency probe and various 0.5 N skilled force assessments for group variables such as age, pure tone hearing assessments, sex, speech usage and smoking history. Future studies will begin the processing of modeling this complex multivariate relationship in healthy individuals before moving to a disordered population

Fostering Clinical and Academic Faculty Collaborations to Improve Graduate Education

Accredited graduate programs in Communication Sciences and Disorders (CSD) work to integrate academic coursework, a breadth of clinical experiences, and an overarching capstone project (e.g. summative assessment). The best graduate programs focus on integrating these three elements through high quality collaborations between academic and clinical faculty. These collaborations are fostered when clinical and academic faculty attempt to provide students with experiences that intersect academic, research, and clinical areas of speech language pathology. The purpose of this paper describes the collaborative efforts undertaken by the CSD department at the Pennsylvania State University. We present a model for collaborations in graduate education and discuss examples of our current integrative projects

Effects of ageing on orofacial fine force control and its relationship with parallel change in sensory perception

Purpose: Current theoretical models suggest the importance of a bidirectional relationship between sensation and production in the vocal tract to maintain lifelong speech skills. The purpose of this study was to assess age-related changes in orofacial skilled force production and to begin defining the orofacial perception-action relationship in healthy adults. Method: Low-level orofacial force control measures (reaction time, rise time, peak force, mean hold force (N) and force hold SD) were collected from 60 adults (19–84 years). Non-parametric Kruskal Wallis tests were performed to identify statistical differences between force and group demographics. Non-parametric Spearman’s rank correlations were completed to compare force measures against previously published sensory data from the same cohort of participants. Result: Significant group differences in force control were found for age, sex, speech usage and smoking status. Significant correlational relationships were identified between labial vibrotactile thresholds and several low-level force control measures collected during step and ramp-and-hold conditions. Conclusion: These findings demonstrate age-related alterations in orofacial force production. Furthermore, correlational analysis suggests as vibrotactile detection thresholds increase, the ability to maintain low-level force control accuracy decreases. Possible clinical applications and treatment consequences of these findings for speech disorders in the ageing population are provided